Preventing the Destruction of Hard-Alloy Inserts in Dies Used for the Production of Nichrome and Ferronichrome Strips

Resumo

Hard-alloy dies with channels of the traditional form and dimensions have been shown to have inadequate resistance to fracture during the drawing of nichrome and ferronichrome strips. Their durability can be improved by favorably directing the forces that are normal to the surface of the channel’s working zone, which reduces the probability of fracture. To do this, a drawing-die insert was made with a drawing channel having an outlet zone equal to 0.24–0.32 of the total length of the channel. Comparison of the traditional channel and the improved channel showed that the effect of the stresses created during service is smoothed out in the weak parts of the die. The effects of the highest stresses and stress intensity are reduced by using an insert with a larger cross section and a more massive yoke.